Are you trying to pull existing data into the new fields? if this is the case then no, it is not possible. Any existing posts created with the old fields would need to be recreated using the new fields. The data for repeaters and flex fields is stored significantly different.
If you are talking about just showing the data that is entered on the front end, the best I can do at this point is point you to the documentation for clone fields, repeaters and flex fields. I’d need more to go on to do more.
I personally do not use clone fields. I’ve tried them on a couple of sites and have always run into issues with them. I can try to help you, but I’ll need more information on exactly where you’re running into the problem.
